Administration device having a patient state monitor

ABSTRACT

Embodiments disclosed herein include systems and methods for administering a drug over a time period. One embodiment of a system includes an administration unit, a housing that houses the administration unit, and a controller unit adapted to receive an alarm triggering signal. Also included in some embodiments is an alarming unit that is adapted to generate an alarm signal on reception of the alarm triggering signal. Some embodiments include a patient state monitor that includes a motion-sensitive sensor unit that is reactive on patient motion. The patient state monitor may be adapted to process a sensor signal generated by the motion-sensitive sensor unit. The patient state monitor may also be adapted to transmit the alarm triggering signal to the controller unit if a patient motion level is below a predefined motion level, as determined by a length of time without patient motion.

CROSS REFERENCE TO RELATED APPLICATIONS

The present application is a Divisional of U.S. patent application Ser.No. 12/901,090 filed Oct. 8, 2010, which is a Continuation ofInternational Application No. PCT/EP2009/002586, filed Apr. 8, 2009,which claims priority to EP Application number 08007186.3, filed Apr.11, 2008, which are each incorporated by reference in their entireties.

TECHNICAL FIELD

Embodiments disclosed herein relate to an administration device for thecontinuous or quasi-continuous administration of a liquid drug over anextended time period and to a method for supervising such anadministration device.

BACKGROUND

Continuous Subcutaneous Insulin Infusion (CSII) is the basis for astate-of-the-art therapy of insulin-dependent diabetes mellitus. In thistherapy, a diabetic patient carries a miniaturized infusion pump nightand day and preferably concealed from view. The infusion pumpadministers insulin by a cannula, (the cannula oftentimes being madefrom medical-grade stainless steel or Teflon), into the subcutaneoustissue. The insulin pump administers insulin in a continuous orquasi-continuous way according to a patient-specific and time-of-daydependent basal profile in order to cover the patient's basal (i.e.,meal-independent) insulin need. In addition, the pump is adapted toadminister comparatively large insulin boli on demand which are requiredfor covering the intake of food, namely carbohydrates, and to correctfor undesirably high blood glucose values. Infusion devices which areadapted for the CSII therapy of diabetes mellitus are disclosed.

A general concern associated with the diabetes therapy based on insulinadministration is the danger of hypoglycemia. While the number ofpotential reasons for this phenomenon is high, it is usually associatedwith a mismatch between blood glucose level and blood insulin level,with the blood insulin level being too high. The effect of hypoglycemicconditions may vary from a lack of concentration to severe perceptualdisturbances, to coma and finally to death. Under normal circumstances,the immediate intake of fast-acting carbohydrates is a sufficientmeasure. However, in some cases, a diabetic may fall into a hypoglycemiccoma very fast without having a chance to act properly.

In a situation of hypoglycemic coma, it is highly desirable to providean alarm signal in order to get emergency support as fast as possible.It is further desirable to stop drug administration almost immediatelyin order to not worsen the situation. Therefore, state-of-the-artinsulin pumps may comprise a ‘dead man's control, which automaticallytriggers the generation of an audible alarm signal and stops insulinadministration if no user interaction with the pump has occurred for agiven alarming time in which a user interaction, such as a bolusadministration, can be assumed to occur. In order to avoid false alarms,the alarming time may, for example, be as along as 12 hours. This is,however, often found to be inappropriate in different ways. On the onehand, the alarming time may be too short. When sleeping longer thannormal (e.g., during the weekend), even a rather long alarming time maybe too short and cause false alarms. Such false alarms are generallyinconvenient and are even found to be dangerous if insulinadministration is stopped due to a false alarm. On the other hand, thealarming time may be too long. If the situation of a hypoglycemic comaoccurs shortly after a user interaction, alarming and potentiallystopping the insulin administration are triggered only with a delay ofmany hours.

SUMMARY

Embodiments disclosed herein include systems and methods foradministering a drug over a time period. One embodiment of a systemincludes an administration unit, a housing that houses theadministration unit, and a controller unit adapted to receive an alarmtriggering signal. Also included in some embodiments is an alarming unitthat is adapted to generate an alarm signal on reception of the alarmtriggering signal. Some embodiments include a patient state monitor thatincludes a motion-sensitive sensor unit that is reactive on patientmotion. The patient state monitor may be adapted to process a sensorsignal generated by the motion-sensitive sensor unit. The patient statemonitor may also be adapted to transmit an alarm triggering signal tothe controller unit if a patient motion level is below a predefinedmotion level, as determined by the length of time without patientmotion.

Similarly, embodiments of a method may include providing anadministration device that is adapted to be carried by a patient, theadministration device being further adapted for drug administration overan extended period of time, the administration device including amotion-sensitive sensor unit, the motion sensitive sensor unit beingreactive on patient motion, processing a sensor signal (SS) generated bythe motion-sensitive sensor unit. Additionally, embodiments of themethod may include generating an alarm triggering signal if processingof the sensor signal (SS) indicates a patient motion level below apredefined motion level, the predefined motion level being defined bythe length of time-periods without patient motion that can be expectedfor a conscious human.

BRIEF DESCRIPTION OF THE DRAWINGS

In the following, exemplary embodiments of administration devicesaccording to the present disclosure and exemplary embodiments of methodsfor detecting a patient motion level below a predefined motion levelaccording to the present disclosure are described in greater detail withreference to the figures.

FIG. 1 depicts an administration device according to one or moreembodiments shown and described herein.

FIG. 2 depicts an internal functional structure of an exemplaryadministration device, such as shown in FIG. 1.

FIG. 3 depicts a schematic structure of an exemplary patient statemonitor of an exemplary administration device.

FIG. 4 qualitatively depicts signals as may be probed in a patient statemonitor according to FIG. 3.

FIG. 5 depicts the schematic structure of a patient state monitor of anexemplary administration device.

FIG. 6 depicts a flow diagram for the operation of an exemplary patientstate monitor according to FIG. 5.

FIG. 7 depicts a schematic structure of a patient state monitor for anexemplary administration device.

FIG. 8 depicts a flow diagram for the operation of an exemplary patientstate monitor according to FIG. 7.

DETAILED DESCRIPTION

Embodiments disclosed herein provide administration devices for thecontinuous or quasi-continuous administration of liquid drugs, such asinsulin. These embodiments may be configured to ensure a short delaytime for alarming an emergency of a coma patient, while avoiding falsealarms. Embodiments disclosed herein may consider patient motion,assuming that a patient is likely to be in a coma if patient motion isbelow a predefined motion level.

In the following, some terms are defined as they are used in the contextof the present disclosure:

The term ‘motion-sensitive sensor unit’ includes sensor units that arereactive on motion. A motion-sensitive sensor unit may temporarilygenerate a sensor signal (SS) as a consequence of motion and/or changeof motion, such as an acceleration sensor. Alternatively oradditionally, the motion sensitive sensor unit may continuously generatea sensor signal (SS) that is changed or modified by motion, such as tiltsensor, the tilt sensor generating a sensor signal (SS) independent ofthe orientation of a measurement vector with respect to gravity.

The term ‘sensor unit’ includes both a single sensor as well anarrangement of multiple sensors. For example, one embodiment of a sensorunit may include at least two single acceleration sensors, with eachsingle sensor being associated with a different measurement vector. Insuch an arrangement, the single sensors may operate according to one ormore physical principle. Accordingly, the sensor signal (SS) may includea single signal or a vector of multiple signals.

The term ‘derived’ in the context of a signal may generally refer to asignal that is obtained from another primary signal by processing suchas amplifying, threshold detection, analog-to-digital conversion,filtering, or the like. A derived signal may also be identical with thecorresponding primary signal.

The term ‘patient motion level’ generally refers to an amount of patientmotion over time. Patient motion may be assessed based on diversecriteria such peak acceleration values, average acceleration values,mean time between consecutive patient motions, duration of continuouspatient motions, duration of time intervals without patient motion, orthe like.

Accordingly, embodiments of an administration device for theadministration of a liquid drug over an extended time period to apatient, include an administration unit, a housing that includes theadministration unit. In some embodiments, the housing is adapted to becarried by a patient over an extend time period. Also included in someembodiments is a controller unit that controls operation of theadministration unit and receives an alarm triggering signal, at leastone alarming unit. The at least one alarming unit may be coupled to thecontroller unit and adapted to generate at least one alarm signal onreception of the alarm triggering signal by the controller unit.

Similarly, some embodiments of an administration device include apatient state monitor that includes a motion-sensitive sensor unit. Themotion-sensitive sensor unit may be reactive on patient motion.Similarly, the patient state monitor may be adapted to process a sensorsignal (SS) that is generated by the motion-sensitive sensor unit andadapted to generate an alarm triggering signal. The patient statemonitor may also be adapted to transmit the alarm triggering signal tothe controller unit if processing of the sensor signal (SS) indicates apatient motion level below a predefined motion level, the predefinedmotion level being defined by the length of time-periods without patientmotion that can be expected for a conscious human.

Similarly, some embodiments of an administration device for theadministration of a liquid drug over an extended time period accordingto the present disclosure include an administration unit and a housingthat includes the administration unit and is adapted to be carried by apatient over an extend time period. The administration device may alsoinclude a controller unit that is adapted to control operation of theadministration unit and to receive an alarm triggering signal. Theadministration device may also include at least one alarming unit thatis coupled to the controller unit and adapted to generate at least onealarm signal on reception of the alarm triggering signal by thecontroller unit. Some embodiments include a patient state monitor thatincludes a motion-sensitive sensor unit that is reactive on patientmotion. The patient state monitor may be adapted to process a sensorsignal (SS) that is generated by the motion-sensitive sensor unit.Similarly, the patient state monitor may be adapted to generate an alarmtriggering signal and to transmit the alarm triggering signal to thecontroller unit if processing of the sensor signal (SS) indicates apatient motion level below a predefined motion level, where thepredefined motion level is defined by the length of time-periods withoutpatient motion that can be expected for a conscious human.

In some embodiments, the administration device includes additionalelements, such as a drug reservoir, a user interface, a power supply, atleast one data interface. Similarly, in some embodiments disclosedherein the controller unit may include elements such as such asapplication specific integrated circuits (ASICs), micro controllers,memory circuits, clock and timer circuits, general digital and analogcircuitry, and the like. The controller unit may also include at leastone micro controller.

Similarly, in some embodiments, the alarming unit includes at least oneof an audio alarm generator (such as a buzzer or loud speaker) and atactile alarm generator (such as a pager vibrator). Further, in someembodiments, the at least one alarming unit is included in the housing.Alternatively or additionally, the alarming unit may include remotealarm generators, such as dedicated alarming devices carried by a thirdperson. In some embodiments, the at least one alarming unit furtherserves as indication unit for general control and operation feedbackpurposes.

In still some embodiments, components of the administration device mayinclude and/or coupled to the housing. In some embodiments, however,some components include and/or are coupled to a least one additionalhousing. For example, the controller unit may, totally or in part, beincluded within an additional controller housing, where the controllerunit and the administration unit are adapted for wireless communication.Similarly, a user interface may, totally or in part, be provided by auser interface housing, the user interface housing being separate fromthe housing, in order to enable convenient and discrete operation.Further housings may be provided if the housing is adapted to beattached substantially directly at the infusion site, (e.g., as a patchor further locations that can not guaranteed to be accessible in an easyand discrete way for user interaction purposes).

According to some embodiments, the patient state monitor includes amotion-sensitive sensor unit. Similarly, the patient state monitor mayinclude further elements such as signal conditioning circuitry,counters, timers, shift registers, energy storages, or the like asdescribed in grater detail below in the framework of exemplaryembodiments. The patient state monitor may, at least in part, beintegral with the controller unit.

In some embodiments, the motion-sensitive sensor unit may be rigidlycoupled to the housing. For this kind of design, any motion of thehousing is directly transferred to the motion-sensitive sensor unit.Similarly, in some embodiments, the motion-sensitive sensor unit isincluded within and/or coupled to a motion sensor housing, the motionsensor housing being separate from the housing.

In some embodiments, the motion-sensitive sensor unit is included withinand/or coupled to a motion sensor unit housing, the motion sensor unithousing being separate from the housing. For example, themotion-sensitive sensor unit may be included with and/or rigidly coupledto a dedicated motion sensor unit housing, the motion sensor unithousing being adapted to be carried, (e.g., as a wrist watch iscarried).

Besides the motion-sensitive sensor unit, the motion sensor unit housingmay include additional elements of the patient state monitor. The motionsensor unit housing may include a wireless motion sensor unit datainterface, where the motion sensor unit data interface is operativelycoupled to the motion-sensitive sensor unit. In such embodiments, themotion sensor unit data interface may be adapted to transmit the sensorsignal (SS) and/or at least one signal derived from the sensor signal(SS). Providing a dedicated motion sensor unit housing such as a wristwatch like motion sensor unit housing allows coupling of themotion-sensitive sensor unit to a patient's arm or leg, which aretypically more likely to move than the patient's body, especially whilesleeping.

In some embodiments of the administration device, the motion-sensitivesensor unit includes at least one of a tilt sensor, a vibration sensor,a shock sensor, and an acceleration sensor. Similarly, in someembodiments, the motion-sensitive sensor unit includes at least one of atilt sensor, a vibration sensor, a shock sensor, and an accelerationsensor. In further embodiments, other kinds of motion-sensitive sensors,such as gyroscopic sensors, are used. Additionally, in some embodiments,the motion-sensitive sensor unit includes at least one binary switchingsensor, such as an acceleration switch, a vibration switch or a tiltswitch. The corresponding sensor signal (SS) reflects the state of thesensor, (i.e., ‘open’ or closed′).

Similarly, some embodiments include at least two binary switchingsensors that have different measurement axes. The measurement axes maybe substantially perpendicular to each other. The at least two binaryswitching sensors may be electrically parallel to form a resultingswitch, the resulting switch being closed if at least one of the binaryswitching sensors is closed.

In some embodiments, the motion-sensitive sensor unit includes at leastone sensor generating a quantitative sensor signal (SS), such as a piezoacceleration sensor, a capacitive acceleration sensor or a gyroscopicsensor. If the motion-sensitive sensor unit includes a piezo electricacceleration sensor, a charge amplifier circuit may be used forcharge-to-voltage conversion purposes, thereby allowing the quantitativeevaluation of acceleration in addition to the qualitative detection ofpatient motion. Since embodiments disclosed herein may be configured todetect the occurrence of substantial patient motion, a charge-generatingpiezo electric sensor may also be directly coupled to ananalog-to-digital conversion circuit such as a Schmitt trigger or thelike, in order to obtain a binary signal.

According to some embodiments that include a motion-sensitive sensorunit comprising at least two single motion-sensitive sensors, thesignals generated by the at least two motion-sensitive sensors are, atleast in part, evaluated independently. Providing a motion-sensitivesensor unit comprising at least two single motion-sensitive sensors isespecially advantageous in order to avoid false alarms because ofpatient motions not being detected by a motion-sensitive sensor havingone fixed measurement axis. Similarly, in some embodiments, the patientstate monitor includes an energy storage and is adapted to modify anenergy (E) stored by the energy storage.

In some embodiments, the patient state monitor includes an energystorage and the motion-sensitive sensor unit that is adapted to modifyan energy (E) is stored by the energy storage. Similarly, in someembodiments, the energy storage includes a capacitor and the energy (E)is stored in the electrical field of the capacitor. Similarly, othertypes of energy storages such as coils or mechanical springs may be usedas energy storage. In some embodiments that include a capacitor asenergy storage, the motion-sensitive sensor unit includes at least onebinary switching sensor, where closing the at least one binary switchingsensor results in fully or partly charging or discharging the capacitor.Similarly, in some embodiments, the controller unit is adapted tocontrol the administration unit to stop drug administration on receptionof the alarm triggering signal.

Further, in some embodiments, the controller unit may be adapted tocontrol the administration unit to stop drug administration on receptionof the alarm triggering signal. Stopping drug administration may bedesirable, such as in the framework of diabetes therapy by CSII in ordernot to worsen the situation in case of a hypoglycemic coma. The patientstate monitor may include a counter that is adapted to count a number Nof consecutive monitoring intervals without substantive patient motion.In still some embodiments, the patient state monitor is adapted togenerate an alarm triggering signal if the counter state N equals athreshold number (TN).

In some embodiments disclosed herein, the patient state monitor isadapted to be selectively deactivated. Similarly, the patient statemonitor may be automatically deactivated for given periods of time perday and/or for given days of a week. For example, the patient statemonitor may be automatically deactivated during night time in order toavoid false alarms. The patient state monitor may also be adapted formanually deactivation by the patient for a given time interval and/oruntil a given time of day. In some embodiments, the patient statemonitor is further adapted to be fully deactivated by the patient and/ora healthcare professional. A patient state monitor may also be includedthat is adapted to be selectively deactivated. The administration devicemay further include a dead man's control unit, that is adapted to beactivated upon deactivation of the patient state monitor. A dead man'scontrol unit may further be provided in addition to the patient statemonitor for safety and redundancy purposes.

In some embodiments, the patient state monitor is, at least in part,adapted to be discontinuously energized. In the context of applicationssuch as diabetes therapy by CSII, power consumption is generallycritical as the power supply is one of the major components determiningthe administration device size. In some embodiments, the patient statemonitor is, at least in part, adapted to be energized only for definedsampling points in time and/or during given sampling intervals and maybe de-energized otherwise. The sensor signal generated by themotion-sensitive sensor unit is preferably not processed if thepatient-state monitor is, at least in part, de-energized.

Discontinuously energizing may affect the patient state monitor as awhole or may affect only some power consuming components of the patientstate monitor, such as the motion-sensitive sensor and signal conditioncircuitry, while not affecting other components such as counters.

Also disclosed herein are embodiments of a method for detecting apatient motion level below a predefined motion level. Such a method fordetecting a patient motion level below a predefined motion level inaccordance with the present disclosure may especially be utilized forsupervising an administration device according to the present disclosureas described above.

More specifically, disclosed herein are embodiments of a method fordetecting patient motion below a predefined motion level. Suchembodiments may include providing an administration device that isadapted to be carried by a patient and for drug administration over anextended period of time. The administration device may include amotion-sensitive sensor unit that is reactive on patient motion.Similarly, some embodiments include processing a sensor signal (SS)generated by the motion-sensitive sensor unit and generating an alarmtriggering signal if processing of the sensor signal (SS) indicates apatient motion level below a predefined motion level, the predefinedmotion level being defined by the length of time-periods without patientmotion that can be expected for a conscious human.

Similarly, some embodiments of a method for detecting a patient motionlevel below a predefined motion level may include providing anadministration device, the administration device being adapted to becarried by a patient and for drug administration over an extended periodof time. The administration device may include a motion-sensitive sensorunit and may be reactive on patient motion. The method may also includeprocessing a sensor signal (SS) generated by the motion-sensitive sensorunit and generating an alarm triggering signal if processing of thesensor signal (SS) indicates a patient motion level below a predefinedmotion level. The predefined motion level may be defined by the lengthof time-periods without patient motion that can be expected for aconscious human. It should be understood that the predefined motionlevel may be given by a minimum motion level that can be expected by aconscious human. A predefined motion level may be different fordifferent patients, for different situations, for different times of day(e.g., for daytime and nighttime), and so on.

Similarly, in some embodiments, the predefined motion level may bedefined by length of time periods without patient motion and the methodincludes generating an alarm triggering signal if processing of thesensor signal (SS) indicates no patient motion for a given alarming timeinterval (AT). For this kind of embodiment, the predefined motion levelis given by the alarming time period AT. In some embodiments, the methodfurther includes the step of generating at least one alarm signal upongeneration of the alarm triggering signal.

Some embodiments of the method may include providing monitoringintervals and counting a number N of consecutive monitoring intervalswithout substantive patient motion. The method may also includegenerating an alarm trigger signal if the number N equals a thresholdnumber N, as described below.

In some embodiments that include generation of at least one alarmsignal, the at least one alarm signal may include at least one of anaudible alarm signal and a tactile alarm signal. The at least one alarmsignal may be generated by at least one alarming unit, where the atleast one alarming unit is included with and/or coupled to theadministration device. In some embodiments, the alarm signal may begenerated remotely, (e.g., by an alarming unit comprised by a remotecontroller). In some embodiments, the alarm signal may be generated bycommercial devices such as a cell phone carried by a health careprofessional and/or a person other than the patient. Similarly, someembodiments include modifying the predefined motion level.

Some embodiments of the method include modifying the predefined motionlevel. More specifically, some embodiments involve an alarming timeinterval (AT), where the method comprises modifying the alarming timeinterval (AT) by a patient and/or a healthcare professional in order toadopt the alarming time interval (AT) to the patient's individualsituation and life style. For example, for a patient being a craftsman,a much shorter alarming time interval (AT) may be appropriate ascompared to an office worker who typically spends several hours sittingat a desk with very little motion. Similarly, in some embodiments, a setof at least two different predefined motion levels is provided and themethod comprises manually or automatically selecting either of the atleast two motion predefined levels.

In still some embodiments, the method includes modifying the predefinedmotion level based on at least one of the following: time of day, day ofweek, and past patient motion. More specifically, some such embodimentsinclude modifying the predefined motion level based on at least one oftime of day, day of week, and past patient motion. For example,embodiments of the method may involve an alarming time interval (AT),and include automatically switching the alarming time interval (AT)between a first alarming time during daytime and a second alarming timeduring night time, the second alarming time being larger than the firstalarming time. In this way, a short alarming delay may be achievedduring the daytime where a lot of patient motion may occur withoutcausing false alarms during night time and especially during sleep whereless patient motion is likely to occur. Similarly, the alarming timeinterval (AT) may be automatically modified to be different for workingdays and weekend days.

In some embodiments, the predefined motion level may be modified basedon past patient motion. For example, if a diabetic person is newlyequipped with an administration device according to embodiments of thepresent disclosure, the alarming time interval (AT) may first be set toa comparatively long default value of, for example, 6 hours.Subsequently, the sensor signal (SS) may be processed and evaluated foran adoption time interval of, for example, 1 month in order to determinethe patient's individual motion habits and motion level. The initialalarming time may subsequently be modified based on the longest timeinterval without substantial patient motion within the adoption timeinterval or based on a quartile, such as the 95% quartile of all periodsof time without substantial patient motion within the adoption timeinterval. In addition to or alternatively to providing a dedicatedadoption time interval, the patient motion level may be monitored andthe predefined motion level may be configured to automatically adapt thepredefined motion level to change in circumstances such as a change fromwork to holidays and vice versa and/or changes in habits or lifestyle ofthe patient.

Further, some embodiments of the method include sampling a patient statesignal (PS), the patient state signal (PS) being identical with and/orderived from the sensor signal (SS) at defined sampling points in times,the sampling points in time defining monitoring intervals. Further, someembodiments include sampling a patient state signal, the patient statesignal being identical to or being derived from the sensor signal (SS)at defined sampling points in times, the sampling points in timedefining monitoring intervals. An alarming time interval (AT) may bedefined by the product of the monitoring interval length MT and athreshold number (TN), such that an alarm triggering signal is generatedif the patient has not moved for TN consecutive monitoring intervals.

In some embodiments, the sensor signal (SS) is continuous and is changedor modified as a result of patient motion, such as the signal generatedby a tilt sensor. In this case, embodiments of the method may includeassuming that the patient has not moved within a given monitoringinterval if the patient state signal (PS) is substantially identical atthe two consecutive sampling points in time bordering the givenmonitoring interval. If for example, the motion-sensitive sensor unitincludes a tilt switch, the method may include assuming that the patienthas not moved within a given monitoring interval if the tilt switch isopen at both of the two consecutive sampling points in time borderingthe given monitoring interval or is closed at both of the consecutivesampling points in time bordering the given monitoring interval.

In still some embodiments, the sensor signal (SS) is generatedtemporarily as a direct consequence of patient motion and/or change ofpatient motion, such as the signal generated by an acceleration sensor.In this case, the method may include modifying the patient state signal(PS) based on the sensor signal (SS) during a monitoring period andsampling the patient state signal at the monitoring points in time.Embodiments also include sampling a patient state signal (PS) at definedmonitoring points in time, the monitoring points in time definingmonitoring intervals, is especially advantageous with respect to energyconsumption in contrast to sampling a patient state signal (PS)continuously. Additionally, some embodiments may include modifying theenergy (E) stored in an energy storage, wherein modifying the energy (E)is triggered by patient motion.

In still some embodiments, the method comprises modifying the energy (E)stored in an energy storage, wherein modifying the energy (E) is, atleast in part, triggered by patient motion. The patient state signal(PS) may be correlated with the energy (E). In some embodiments, themethod includes modifying the energy (E) to change between a firstenergy E_1 and a second energy E_2, where the first energy E_1 isdifferent than the second energy. In still embodiments, the methodincludes modifying the energy (E) stored by a capacitor, the capacitormaking up the energy storage and the capacitor voltage U_C making up thepatient state signal (PS). In embodiments involving an alarming timeinterval (AT), where the alarming time interval (AT) is defined by theproduct of a monitoring interval length and a threshold number (TN), themotion-sensitive sensor may include an acceleration switch.

Similarly, embodiments of the method may include sampling the capacitorvoltage U_C and comparing the capacitor voltage U_C with a thresholdvoltage U_T. If the capacitor voltage U_C is below the threshold voltageU_T, the method may include resetting a counter, the counter countingthe number N of consecutive monitoring intervals without substantialpatient motion, charging the capacitor to a capacitor voltage U_C=U_0,followed by starting a new monitoring interval, and during themonitoring interval, discharging the capacitor to a voltage U_C=0 if theacceleration switch is closed. Similarly, some embodiments includecontinuing with sampling the capacitor at the end of the monitoringinterval.

If the capacitor voltage U_C is above the threshold voltage U_T, themethod may include incrementing the counter state N of the counter byone. Similarly, if the counter state N equals a threshold number (TN),the method may include generating an alarm triggering signal. If thecounter state N is lower than the threshold number (TN), the method mayinclude continuing with charging the capacitor.

In embodiments that include sampling a patient state signal (PS), thepatient state signal (PS) being identical to and/or derived from thesensor signal (SS), during sampling intervals, the sampling intervalsmay alternate with non-sampling intervals. Similarly, some embodimentsinclude sampling a patient state signal (PS), where the patient statesignal (PS) is identical to or derived from the sensor signal (SS),during sampling intervals, the sampling intervals alternating withnon-sampling intervals. During sampling interval, embodiments mayinclude sampling the patient state signal (PS) continuously orquasi-continuously. In some embodiments, the sampling interval length(ST) is not constant but is limited not to exceed a maximum samplinginterval length (ST)_max, while the non-sampling interval length NST isconstant.

Similarly, some embodiments include resetting and starting a samplingtimer, the sampling timer measuring the sampling time t during asampling interval. Some embodiments may include continuously or quasicontinuously sampling the patient state signal (PS) until the samplingtime t equals the maximum sampling interval length (ST)_max or thepatient state signal (PS) indicates a substantial patient motion. If thesampling time t does not equal the maximum sampling interval length(ST)_max, embodiments may include stopping the sampling timer andwaiting for a non-sampling interval, the non sampling interval having agiven non sampling interval length NST, followed by continuing withresetting and sampling the sampling timer. If the sampling time t equalsthe maximum sampling interval length (ST)_max, generating an alarmtriggering signal.

For such embodiments, the predefined motion level may be defined by amaximum time without patient motion and an alarming time interval (AT)may be given by the sum of the maximum sampling interval length (ST)_maxand the non sampling interval length NST. The maximum sampling intervallength (ST)_max may be chosen such that at least one patient motionoccurs during a sampling interval if the patient is not in a coma. Forexample, the non-sampling interval length NST may be chosen to be 15minutes and the maximum sampling interval length (ST)_max may be chosento be 45 minutes, resulting in a an alarming time interval (AT) of 1hour.

Non-sampling intervals may be utilized to reduce energy consumption. Inembodiments comprising non-sampling intervals, embodiments may includeenergizing a patient state monitor, at least in part, discontinuously.For example, a motion-sensitive sensor unit and additional signalconditioning circuitry may not be energized during non-samplingintervals.

In some embodiments, the method may include controlling anadministration unit, the administration unit being comprised by theadministration device, to stop drug administration along with generationof the alarm triggering signal. Similarly, the method may also includecontrolling an administration unit, the administration unit includedwith the administration device, to stop drug administration along withgeneration of the alarm triggering signal.

Referring now to the drawings, FIG. 1 depicts an administration deviceaccording to exemplary embodiments of the disclosure. Similarly, FIG. 2reflects the internal structure of an embodiment of the administrationdevice schematically. Such an embodiment may be suited and designed forthe insulin administration in the framework of diabetes therapy usingCSII and the following description of exemplary embodiments refers todiabetes therapy. In the following, reference is first made to FIG. 1and to FIG. 2.

The administration device includes a housing 10, the housing 10enclosing the other device components. The housing 10 is adapted to beworn by a patient during both night and day and is adapted to be carriedwithout attracting attention (e.g., in a belt holster). Theadministration device may further be carried concealed from view, suchas in a trousers pocket, as a necklace, or the like.

The administration device includes a drug reservoir 20, an infusion line27, 29 and an infusion line adapter 25, the infusion line adapter 25coupling the infusion line 29 to the drug reservoir 20. The housing 10,the drug reservoir 20 and the infusion line adapter 25 are designed toform a sealed and watertight unit in the assembled state shown inFIG. 1. The infusion line 29 is connected to an infusion cannula (notvisible in the figures). The infusion cannula is placed in thesubcutaneous tissue and is replaced by the patient every few days. Thedrug reservoir 20 may, for example, hold 3.15 ml of insulin, with eachml of insulin corresponding to 100 International Units (IU) of insulin.

Referring now to FIG. 2, the exemplary administration devices include auser interface 50, the user interface 50 comprising four pushbuttons 42,44, 46, 48, a display 30, an alarming unit 33 in form of a buzzer and aalarming unit 35 in form of a pager vibrator. The display 30 is agraphical Liquid Crystal Display (LCD) and is used to provideinformation that is utilized for this kind of device, such as operationmode information, time and date, drug bolus information, current basalinfusion rate information, menu items for programming the administrationdevice, alerts and error messages, and the like. The alarming unit 33and the alarming unit 35 are provided for generating non-visual userfeedback signals and further serve as alarming unit.

For performing the drug administration, a pump unit 60 and a supervisionunit 63 are provided. In this exemplary embodiment, the pump unit 60includes a motor-driven spindle drive and the supervision unit 63includes a force sensor and a rotary encoder. In combination, the drugreservoir 20 (FIG. 1), the pump unit 60 and the supervision unit 63 formthe administration unit 70. Several suitable designs for the pump unit60 may be designed.

The operation of the administration device is controlled by thecontroller unit 80. The Controller unit 80 is realized as an electronicscircuit and includes all the elements typically comprised by the controlcircuit of this kind of administration devices, such as one or multiplemicro controllers, static and dynamic memory, a clock circuit, a powercircuit for controlling the pump unit 60, safety circuits, and the like.The controller unit 80 is connected to a power supply such as arechargeable or non-rechargeable battery.

The administration device further comprises two bidirectional datainterfaces, namely an infrared (IR) data interface 90 and an RadioFrequency RF data interface 95, according, e.g., to the BLUETOOTH™standard for multiple configuration, remote control and data exchangepurposes which are typical for this kind of device.

The exemplary administration device further comprises a patient statemonitor 100, 100′, 100″. While both the structure of the patient statemonitor 100, 100′, 100″ and the method detecting a patient-motion levelbelow a predefined motion level are in part dependent on the specificembodiment of the patient state monitor 100, 100′, 100″, the generaldesign of the administration device as shown in FIG. 1 and FIG. 2 and asdescribed above may be identical for all exemplary embodiments of thisdisclosure. In addition, it will be understood that the exemplaryembodiments of the patient state monitor 100, 100′ and the exemplarymethods for controlling the operation of the administration device arenot limited to administration devices of this specific structure.

It should be noted that the patient state monitor 100, 100′, 100″ isshown separated from the controller unit 80, while the patient statemonitor 100, 100′, 100″ may be partly integral with the controller unit80 in the technical implementation. The program flow for the operationof the patient state monitor 100, 100′, 100″ and the program flow forsupervising the administration device according to the presentdisclosure may be considered as part of the general program flow forcontrolling the administration device. In particular, timing and programflow are generally controlled by the controller unit 80 for allexemplary embodiments described below in greater detail.

FIG. 3 shows the schematic structure of a patient state monitor 100according to an exemplary embodiment. In the following, when referringto dedicated electronics components like resistors or switches as such,numeral reference signs are used while alpha numeric reference signs,such as ‘R_1’, ‘S_2’, are used to refer to the value of an element suchas a resistor, or a state of an element such as a switch.

The patient state monitor 100 includes a constant voltage supply 110 ofvoltage U_0, a charging resistor 115 of resistance R_1, a capacitor 125of capacity (C), the capacitor 125 serving as energy storage, adischarging resistor 135 of resistance R2, and an acceleration switch140, the acceleration switch 140 acting as motion-sensitive sensor unit.Instead of an acceleration switch, other kinds of switches may be usedthat are normally open and close temporarily due to motion, such asvibration switch or shock switch. The design may further be modified touse switches which are normally closed and open temporarily due tomotion.

The patient state monitor 100 further includes a charging switch 120 anda coupling switch 130. The charging switch 120, as well as the couplingswitch 130, are controlled by the controller unit 80 and may be realizedas solid state semiconductor switches, but may also be realized aselectromechanical switches such as micro reed relays. The patient statemonitor 100 further includes a voltage threshold detector 145, thevoltage threshold detector 145 being operatively coupled to thecapacitor 125 and to a counter unit 150. The voltage threshold detector145 may, for example, be realized as a Schmitt trigger or may berealized by a quantitative analog-to-digital converter, where thedigital output of the converter is compared to a corresponding thresholdnumber. The voltage threshold detector 145 may also include additionalsignal conditioning components such as voltage level converters,filters, or the like.

The acceleration switch 140 is normally open and is closed if it isexposed to an acceleration a in the direction defined by the measurementvector 160, the acceleration a exceeding a given threshold acceleration.Such acceleration switches are, among others, supplied by AssemtechEurope Ltd, UK.

In the following, operation of the patient state monitor 100 isdescribed with reference to both FIG. 3 and FIG. 4. FIG. 4 qualitativelyreflects major signals as may be probed in a patient state monitor 100according to FIG. 3 as a function of time t. For all switches, ‘o’indicates an open switch while ‘c’ indicates a closed switch. Thecapacitor 125 is assumed to be fully discharged in an initial state,resulting in the capacitor voltage U_C to be substantially zero. Thesensor signal (SS) is made up by the status of the acceleration switch140 while the patient state signal (PS) is made up be the capacitorvoltage U_C.

As indicated by the curve 205, the charging switch 120 is closedperiodically, the period defining the monitoring interval 210 ofmonitoring interval length MT. The closing time of the charging switch120 is generally short, but is sufficient to charge the capacitor 125 toa capacitor voltage U_C 240, which may be substantially equal to thevoltage U_0 via the charging resistor 115, resulting the energy (E)stored by the capacitor to be E=E_1=0.5*C*U_0 ².

For example, the capacitor 125 may be designed to have a value of C=100pF while the charging resistor 115 may be designed to have a value ofR_1=100 kΩ, resulting in a charging time constant of τ_1=R_1*C=10 μsecand the closing time of charging switch 120 may be chosen as 4*τ_1. Onthe one hand, small values are preferable for both the charging resistor115 and the capacitor 125 in order to achieve a small charging timeconstant τ_1. On the other hand, a small charging current is desirable,resulting in a lower limit for the value R_1 of the charging resistor115.

After charging the capacitor 125, and assuming the coupling switch 130to be closed, closing the acceleration switch 140 results in thecapacitor 125 being discharged via the discharging resistor 135, therebyresulting in the capacitor voltage U_C. Thus, the energy (E) stored bythe capacitor 125 after discharging may fall substantially to E=E_2=0.The dimension of the discharging resistor R_2 is such that thedischarging time constant τ_2=R_2*C is short enough to ensuresubstantially full discharging of the capacitor 125 if the accelerationswitch 140 is closed for a time of some microseconds. With a dimensionof the capacitor as given above, the value R_2 of the dischargingresistor 135 may be chosen to 1 kΩ The purpose of the dischargingresistor 135 is to limit the discharging current of the capacitor 125and may not be required at all if the capacity (C) of the capacitor 125is sufficiently small and the acceleration switch 140 is designed forthe resulting discharging current.

In FIG. 4, curve 215 showing the state of the acceleration switch 140and the pulse 220 indicates a patient motion. If the patient has notmoved within the monitoring interval 210, the capacitor voltage U_C doesnot substantially change within the corresponding monitoring interval210, i.e., it substantially stays at the level U_0.

As indicated by the curve ‘S’, 230, the capacitor voltage U_C 235 issampled at the beginning of each monitoring interval 210 virtuallyimmediately prior to closing the charging switch 120 and is comparedwith a threshold voltage U_T by the voltage threshold detector 145. Thethreshold voltage U_T is chosen such that the capacitor voltage U_C doesnot fall below the threshold voltage U_T due to leakage of the capacitor125 but does certainly fall below the threshold voltage U_T if at leastone patient motion resulting in closing the acceleration switch 140occurs in the monitoring interval 210. The threshold voltage U_T may befixed to, e.g., (0.8 . . . 0.9)*U_0.

The binary output of the voltage threshold detector 145 is sent to thecounter unit 150. The counter unit 150 includes a counter counting thenumber N of consecutive monitoring intervals without substantial patientmotion. A comparator is also included to compare the counter state Nwith a threshold number (TN). If the patient has moved within the pastmonitoring interval 210, (for example, if the capacitor voltage U_C isbelow the threshold voltage U_T), the counter is reset to zero,otherwise the number N is incremented by one.

The alarming time interval (AT) is given by the product of themonitoring interval length MT and the threshold number (TN). If nopatient motion has occurred for TN consecutive monitoring intervals 210,an alarm triggering signal is generated by the comparator that isincluded within the counter unit 150 and is transmitted to thecontroller unit 80. Along with controlling the acoustical indicator 33and/or the alarming unit 35 to generate alarm signals, a correspondingalarm message is displayed on the display 30 and the administration unit70 is instructed to stop drug administration. While charging thecapacitor 125, the capacitor 125 may be decoupled from the accelerationswitch 140 via the coupling switch 130 in order to prevent the capacitor125 to be charged improperly or incompletely due to a patient motionwhich may occur during charging.

The monitoring interval length MT may principally be similar (and/oridentical) to the alarming time interval (AT), resulting in the TN=1.However, this signifies that the capacitor 125 is virtually free fromleakage. The alarming time interval (AT), for example, may be set to atypical value of 1 hour. During this period of time, the capacitorvoltage U_C may fall from U_0 below U_T due to leakage even if theacceleration switch is permanently open. The length MT of the monitoringinterval 210 is therefore chosen to be substantially shorter than thealarming time interval (AT). Depending on the leakage properties of thecapacitor 125, the monitoring interval length may be chosen to be, forexample, 3 minutes. This results in the threshold number (TN)=20 for thealarming time interval (AT) being 1 hour. According to a modification ofthis exemplary embodiment, capacitor leakage is taken into account bysuccessively lowering the threshold voltage U_T within a monitoringinterval such that the capacitor voltage U_C does not fall below thethreshold voltage U_T within a monitoring interval because of capacitorleakage.

The exemplary embodiment of the patient state monitor 100 as describedabove may be slightly modified for energy efficiency purposes. Insteadof closing the charging switch 120 at the beginning of each monitoringinterval 210, it may be closed in order to recharge the capacitor 125 ifthe capacitor voltage U_C has fallen below a charging threshold voltageU_CT. The charging threshold voltage U_T is selected such that thecapacitor voltage U_C will not fall below the threshold voltage U_Twithin the following monitoring interval 210 due to capacitor leakage,with U_T<U_CT<U_0. It should be noted that the patient state monitor 100of this exemplary embodiment is designed to detect if the patient hasmoved within a monitoring interval 210.

According to another exemplary embodiment, the capacity (C) of thecapacitor 125 is considerably larger such that the capacitor istypically not fully discharged if the acceleration switch is temporarilyclosed due to a patient motion and the capacitor voltage U_C isevaluated quantitatively at the beginning of each monitoring interval.In this case, the capacitor voltage U_C prior to charging is generallyeither substantially equal to voltage U_0 nor to substantially equal tozero, but may take any value between zero and U_C, dependent on howoften and how long the acceleration switch 140 was closed during thepast monitoring interval due to acceleration. By evaluating thecapacitor voltage U_C, the patient motion level can be assessedquantitatively besides detecting if a patient motion has occurred. In afurther modification, the charging switch 120 is not closed for fixedperiods of time for charging the capacitor 125, but the capacitorvoltage U_C is sampled during charging and the charging switch 125 isopened when the capacitor 125 is substantially fully charged.

FIG. 5 shows the schematic structure of a patient state monitor 100′according to a another exemplary embodiment. For this kind ofembodiment, the motion-sensitive sensor unit 140′ is a switch which maybe both statically open and/or statically closed as long as the patientdoes not substantially move and may change from ‘open’ to ‘closed’ andvice versa due to patient motion. The motion-sensitive sensor unit 140′may especially be a tilt switch which is open or closed in dependence ofthe orientation of a measurement vector 160′ with respect to gravity.The state of the tilt switch 140′ makes up the sensor signal (SS).

In addition to the tilt switch 140′, the patient state monitor 100′includes a resistor 165 serving as a pull-up resistor, resulting in theswitch voltage U_S being substantially equal to voltage U_0 110′ withrespect to ground if the tilt switch 140′ is open and to besubstantially zero with respect to ground if the tilt switch 140′ isclosed. The switch voltage U_S makes up the patient state signal (PS)with U_S=U_C representing a Boolean ‘1’ (tilt switch 140′ open) andU_S=0 representing a Boolean ‘0’ (tilt switch 140′ closed). The patientstate monitor 100′ further comprises a comparison unit 170, thecomparison unit 170 including a two-stage 1 Bit shift register forstoring the state of the tilt switch 140′ and an XOR-logic. The patientstate monitor 100′ further includes a counter unit 150′. Even though notexplicitly shown in FIG. 5, the patient state monitor 100′ may includeadditional supplementary components such as a Schmitt trigger forconverting the switch voltage U_S into a binary signal.

In the following, reference is made to FIG. 5 as well as to the FIG. 6,the flow diagram provided by FIG. 6 representing the operation of thepatient state monitor 100′. In block 400, the state of the tilt switch140′ is stored in the first register Reg_1 of the shift register ofcomparison unit 170. After waiting for a monitoring interval, themonitoring interval having a monitoring interval length MT in block 405,the contents of the first register Reg_1 is shifted to the secondregister Reg_2 and while the current state of the tilt switch 140′ isstored in the first register Reg_1 in step 410.

In block 415, the contents of the first register Reg_1 and the secondregister Reg_2 are compared by an XOR-Logic included in the comparisonunit 170. If the contents of both registers Reg_1 and Reg_2 isdifferent, (for example, either of the registers comprise a ‘Boolean 0’while the other of the registers comprises a Boolean ‘1’), it can beassumed that the patient has moved in the past monitoring interval. Inthis case, a counter counting the number N of consecutive monitoringintervals without substantial patient motion, the counter being includedwithin the counter unit 150′, is reset in block 420 and a new monitoringinterval is started with block 405.

If the contents of both registers Reg_1 and Reg_2 is identical, (i.e.both of the registers either comprise a ‘Boolean 1’ or a ‘Boolean 0’),the patient may not have moved within the past monitoring interval, orthe patient may have moved such that the state of the tilt switch 140′in block 410 is identical to the state of the tilt switch 140′ in block400. In this case, the counter comprised by the counter unit 150′ isincremented by one in block 425 and the counter state N is compared witha threshold number (TN) in block 430 by a comparator included with thecounter unit 150′. If the counter state equals the threshold number(TN), an alarm triggering signal is generated by the counter unit 150′and transmitted to the controller unit in block 435. Otherwise a newmonitoring interval is started with block 405.

It should be noted that a patient motion within a monitoring interval isnot necessarily detected according to this type of exemplary embodiment.In order to prevent the generation of false alarms, it is thereforepossible to choose the threshold number (TN) somewhat larger as comparedto a design which ensures each patient motion within a monitoringinterval to be detected. The threshold number (TN) may be selected suchthat the probability of only undetected patient motion within TNconsecutive monitoring intervals is virtually zero. For example,assuming a monitoring interval length MT of 3 minutes, the thresholdnumber (TN) may be chosen to 40.

FIG. 7 depicts a schematic structure of a patient state monitor 100″according to a another exemplary embodiment. For this kind ofembodiment, the motion-sensitive sensor unit is a piezo electricacceleration sensor 200 generating a charge Q when being accelerated,the charge Q being proportional to the acceleration. Following theacceleration sensor 200, the patient state monitor 100″ comprises acharge amplifier 205, the charge amplifier 205 converting the charge Qinto a charge proportional voltage U_Q. The charge Q makes up the sensorsignal (SS). The patient state monitor 100″ further includes a pulseformer 210, the pulse former 210 generating a triggering pulse upon afalling edge or rising edge of the charge proportional voltage Q_C. Theoutput of the pulse former 210 makes up the patient state signal (PS).The patient state monitor 100″ further includes a sampling timer 220,and a hold off-timer 225. The hold-off timer 225 is adapted toselectively energize the charge amplifier 205 and the pulse former 210.Both the sampling timer 220 and the hold-off timer include a timer and acomparator to compare the timer state with a threshold time and togenerate an output signal resulting from the comparison. For thesampling timer, the corresponding threshold time is made up by themaximum sampling interval length (ST)_max, for the hold-off timer thecorresponding threshold time is made up by the non-sampling intervallength NST.

In the following, reference is made to FIG. 7 as well as to FIG. 8. Theflow diagram provided by FIG. 8 represents the operation of the patientstate monitor 100″. In block 450 of FIG. 8, a sampling interval isstarted by resetting and starting the sampling timer 220, the samplingtimer 220 counting the sampling time t. In block 455, the output of thepulse former 210 is sampled. A pulse generated by the pulse former 210may be indicative for either of a positive or negative pulse of thecharge proportional voltage U_Q as a consequence from an accelerationpulse measured by the piezo electric acceleration sensor 200. In thiscase, the hold-off timer disenergizes the charge amplifier 205 and thepulse former 210 and stops the sampling timer 220, followed by waitingfor a non-sampling interval having a non-sampling interval length NST inblock 460. At the end of the non-sampling interval, the charge amplifier205 and the pulse former 205 are reenergized and a new sampling intervalis started with block 450.

If no pulse is detected at the output of the pulse former 210 in block455, the sampling time t as measured by the sampling timer 220 iscompared to the maximum sampling interval length (ST)_max in block 465.If the sampling time t equals the maximum sampling interval length(ST)_max, an alarm triggering signal is generated in block 470.Otherwise, the output of the pulse former 210 is sampled again in block455.

The non sampling interval length NST may be chosen such that at leastone patient motion occurs during the sampling interval if the patient isnot in a coma. For example, the non-sampling interval length NST may bechosen to be 15 minutes and the maximum sampling interval length(ST)_max may be chosen to be 45 minutes, resulting in an alarming timeinterval (AT) of 1 hour. The non-sampling interval length NST mayfurther be adaptive and may especially be shorter during night time ascompared to daytime or may not be present at all. According to amodification of this exemplary embodiment, the sensor signal isevaluated quantitatively and the patient state signal (PS) is given bythe average acceleration level within a sampling interval and thepredefined motion level is given by a threshold average accelerationlevel.

For at least some of the exemplary embodiments, the alarming timeinterval (AT) is initially set to a long time (for example, 6 hours),according to the configuration of a health care professional.Subsequently, the sensor signal (SS) is processed and evaluated for anadoption time interval of, for example, 1 month, in order to determinethe patient's individual motion habits and amount of motion. Anappropriate value for the alarming time interval (AT) may subsequentlybe determined as the longest time interval (LT) without substantialpatient motion within the adoption time interval. An additional safetymargin is added to this value to make up the alarming time in orderavoid false alarms. The safety margin may be a fixed amount of time of(such as 30 minutes), which is added to longest time interval (LT)without substantial patient motion within the adoption time interval ormay be defined in dependence of the longest time interval (LT) withoutsubstantial patient motion within the adoption time interval bymultiplying it with a safety factor of, for example, 1.1, the safetyfactor being larger than one. Additionally, for at least some of theexemplary embodiments, the alarm triggering signal may further oralternatively be transmitted to a separate user interface, to a cellphone, or the like.

Therefore, at least the following is claimed:
 1. A method for detectinga patient motion level below a predefined motion level, comprising:providing: an administration unit; a housing that houses theadministration unit, the housing being adapted to be carried by apatient over an extended time period; a controller unit adapted tocontrol operation of the administration unit, the controller unitfurther adapted to receive an alarm triggering signal; an alarming unitthat is coupled to the controller unit, the alarming unit adapted togenerate an alarm signal on reception of the alarm triggering signal bythe controller unit; and a patient state monitor that includes amotion-sensitive sensor unit, the motion-sensitive sensor unit beingreactive on patient motion, the patient state monitor being adapted toprocess a sensor signal (SS) generated by the motion-sensitive sensorunit, and a counter unit adapted to generate the alarm triggering signaland to transmit the alarm triggering signal to the controller unit ifprocessing of the sensor signal (SS) indicates the patient motion levelis below the predefined motion level, the predefined motion level beingdefined by a length of time-periods without patient motion that can beexpected for a conscious human; and generating, by the motion-sensitivesensor unit, the sensor signal (SS); processing, by the patient statemonitor, the sensor signal (SS); and generating, by the counter unit,the alarm triggering signal.
 2. The method of claim 1 further comprisingtransmitting the alarm triggering signal to the controller unit.
 3. Themethod of claim 1 further comprising stopping, by the controller unit, adrug administration on reception of the alarm triggering signal.
 4. Themethod of claim 1 further comprising changing a state of at least onebinary switching sensor for generating the sensor signal (SS).
 5. Themethod of claim 1 further comprising providing, as part of themotion-sensitive sensor unit, a piezo electric acceleration sensor, andusing a charge amplifier circuit for charge-to-voltage conversionpurposes, and evaluating quantitatively an acceleration in addition toqualitatively detecting the patient motion.
 6. The method of claim 1further comprising providing a wireless motion sensor unit datainterface operatively coupled to the motion-sensitive sensor unit, andcoupling the motion-sensitive sensor unit to an arm or a leg of thepatient.
 7. The method of claim 1 further comprising providing, as partof the motion-sensitive sensor unit, at least two singlemotion-sensitive sensors, and evaluating independently signals generatedby the at least two motion-sensitive sensors to avoid false alarms.